<?php declare(strict_types=1);
/*
 * This file is part of phpunit/php-code-coverage.
 *
 * (c) Sebastian Bergmann <sebastian@phpunit.de>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace SebastianBergmann\CodeCoverage\Util;

use function round;
use function sprintf;
use RoundingMode;

/**
 * @internal This class is not covered by the backward compatibility promise for phpunit/php-code-coverage
 *
 * @no-named-arguments Parameter names are not covered by the backward compatibility promise for phpunit/php-code-coverage
 */
final readonly class Percentage
{
    private float $fraction;
    private float $total;

    public static function fromFractionAndTotal(float $fraction, float $total): self
    {
        return new self($fraction, $total);
    }

    private function __construct(float $fraction, float $total)
    {
        $this->fraction = $fraction;
        $this->total    = $total;
    }

    public function asFloat(): float
    {
        if ($this->total > 0) {
            return ($this->fraction / $this->total) * 100;
        }

        return 100.0;
    }

    public function asString(): string
    {
        if ($this->total > 0) {
            return sprintf('%01.2F%%', $this->asFloatRoundedTowardsZero());
        }

        return '';
    }

    public function asStringWithoutPercentSign(): string
    {
        if ($this->total > 0) {
            return sprintf('%01.2F', $this->asFloatRoundedTowardsZero());
        }

        return '';
    }

    public function asFixedWidthString(): string
    {
        if ($this->total > 0) {
            return sprintf('%6.2F%%', $this->asFloatRoundedTowardsZero());
        }

        return '';
    }

    /**
     * Rounding towards zero ensures that a percentage is never displayed
     * as reached (for instance "100.00%") when it is actually below that
     * threshold (for instance 99.999%).
     */
    private function asFloatRoundedTowardsZero(): float
    {
        return round($this->asFloat(), 2, RoundingMode::TowardsZero);
    }
}
